Tanya O'Carroll is a technology and human rights adviser at Amnesty International.

When the colleagues of Ali Gharavi and Peter Steudtner heard that they had been detained in Turkey, along with representatives of six renowned Turkish NGOs, they assumed there had been a misunderstanding. Ali, a Swedish IT strategy consultant, and Peter, a German nonviolence and wellbeing trainer, had been in Istanbul delivering a routine workshop, as they had done many times before in countries as far afield as Mexico and Pakistan. This was the first time their work had landed them in a police station.

But the detention of the two trainers was no accident. Earlier this month, after 12 days in police custody, both men were remanded in prison along with four others including İdil Eser, the director of Amnesty Turkey. They are facing absurd and baseless allegations of terror links, and lengthy pre-trial detentions.

The workshop Ali and Peter were running, which focused broadly on security and wellbeing for human rights defenders, also covered digital security – how to stay safe online. This is anathema to the Turkish authorities, increasingly intolerant of any dissent, and probably placed the trainers in the government crosshairs from the minute they set foot in Turkey. An opinion piece published in the state-run Turkish daily Türkiye a week after Ali and Peter were detained described with chilling candour how "intelligence services were following [the workshop] at its planning stage….They knew everything right down to their breathing."

Ali and Peter are described as orchestrators of an "uprising", with training on "mobile equipment security, secure apps and secure communications" cited as evidence. These allegations are ludicrous. Ali is a friend and colleague of mine, and over the years I have been lucky enough to join some of his workshops. Far from the "high-tech underground trainings" of the Turkish government's imagination, these workshops cover the basics of staying safe online: simple best practices like installing two-factor authentication on social media and creating strong passwords.

Protecting sensitive data from unwanted access or surveillance is an essential part of working in the modern world, but it is doubly important for those whose work on behalf of human rights has made them an unwitting target of the state. In the 12 months following the violent coup attempt in July 2016, the human rights situation in Turkey has been in freefall and people have had many of their basic rights crushed. Newspapers, universities and NGOs have hemorrhaged staff as freedom of expression and human rights work have been redefined as crimes.

The jailing of Ali and Peter is the latest sign that the net is widening to include technologists. A week after they were detained, arrest warrants were put out for more than 100 IT employees, including former staff from Turkey's scientific research council TÜBITAK and the telecommunications authority. The Turkish authorities have long been suspicious of online communication and have repeatedly blocked social media services like Facebook, Twitter and YouTube, and thousands of websites are blocked in Turkey. In 2015 the government detained three VICE journalists on suspicion of terrorism, based purely on their use of encryption software.

But the Turkish authorities aren't actually technophobes, and have been quick to take advantage of the surveillance opportunities thrown up by digital communications. Worryingly, the UK's Department of International Trade released information earlier this month (in response to a Motherboard FOI request) showing that it had granted licences to a law-enforcement agency in Turkey for telecommunications interception software in the first quarter of this year. This appears to be in clear contravention of existing rules, as Turkey's purge was well underway when the licences were issued. At the very least, the UK government should be insisting on guarantees from Ankara—the capital of Turkey—that the software is not used as part of any crackdown on human rights activity.

It's not just in Turkey that digital security and encryption are under attack. Technology has increased people's options for freedom of expression and the backlash is growing, with governments around the world blocking or criminalizing the use of security apps to silence ideas they don't like.

Egypt and the United Arab Emirates have both previously blocked encrypted messaging app Signal, while in Morocco seven journalists are facing trial for running a citizen journalism training program that facilitated anonymous publication using a smartphone app. As more aspects of human rights work have moved into the digital sphere, so have the means of attacking and silencing it.

In detaining the workshop participants the Turkish authorities have inadvertently proved exactly why digital security and encryption are important. The speed of Turkey's human rights decline is the ultimate rebuke to the argument that people with nothing to hide don't need to defend their privacy. Whether what you are doing is worth hiding is down to the discretion of your government— and governments can be capricious, as Turkey's embattled civil society has found out.

When they were dragged away by police, our friends Ali and Peter were educating and helping Turkish human rights defenders understand and protect their digital rights in this frightening, shifting new environment. Their detention is a reminder that none of us can afford to be complacent about privacy online—and that our smartphone and laptop screens are becoming new frontiers in the battle for human rights.